Bunch-o-questions about drag racing-Knock retard-Drag Radials-Wheel Hop
11-12-2007, 02:47 PM
#1
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Bunch-o-questions about drag racing-Knock retard-Drag Radials-Wheel Hop The setup:
99 FRC 6speed- H/C/I/ all bolt-ons + 175 = shot 588 RWHP 664TQ on mustang dyno
3.90 gears
18" BFG DR @ 20psi
Spray 3000-6000 RPM on full bottles heated to 1000 psi
launch at 2500-2800 rpm
Problems at the track:
Wheel hop
Lots a spin
Knock retard??
1.8-1.9 60 fts
118 traps
mid 12-13 sec runs = WTF?
nailing every shift @ 6200
I need some damn help.. the current theory is wheel hop and hard shifts = knock retard and killing my power, and im running the rest of the track amputated. Why so much wheel hop on DR @ 20 psi? Spray was not hitting hard at all. Im gonna break all the lines and inspect/clean them and install a plate - delete nozzle. Ideas?
99 FRC 6speed- H/C/I/ all bolt-ons + 175 = shot 588 RWHP 664TQ on mustang dyno
3.90 gears
18" BFG DR @ 20psi
Spray 3000-6000 RPM on full bottles heated to 1000 psi
launch at 2500-2800 rpm
Problems at the track:
Wheel hop
Lots a spin
Knock retard??
1.8-1.9 60 fts
118 traps
mid 12-13 sec runs = WTF?
nailing every shift @ 6200
I need some damn help.. the current theory is wheel hop and hard shifts = knock retard and killing my power, and im running the rest of the track amputated. Why so much wheel hop on DR @ 20 psi? Spray was not hitting hard at all. Im gonna break all the lines and inspect/clean them and install a plate - delete nozzle. Ideas?
11-12-2007, 02:57 PM
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I would look into one of these: www.scangauge.com. Best 160 bucks ever.
Monitor your IAT, IGN, MAP, & AFR. Sounds to me like someone needs to check their tune. What plugs you running?
Wheel hop or hard spin wouldn't hold back your traps THAT much with those numbers, if accurate.
Monitor your IAT, IGN, MAP, & AFR. Sounds to me like someone needs to check their tune. What plugs you running?
Wheel hop or hard spin wouldn't hold back your traps THAT much with those numbers, if accurate.
Last edited by 04blowngoat; 11-12-2007 at 03:08 PM.
11-12-2007, 03:03 PM
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I have two Interceptor OBD2 scan gauges http://www.neweraperformanceparts.com/default.asp?S=503&A=E&PKV=interceptc5|0 i need to hook up.. the will be on the car when we go back..
The spray wasnt hitting hard at all ..gauge on full bottles was steady @ 1000psi.. im gonna break and clean lines
The spray wasnt hitting hard at all ..gauge on full bottles was steady @ 1000psi.. im gonna break and clean lines
Last edited by Dr.Accumulator; 11-12-2007 at 03:09 PM.
11-12-2007, 03:05 PM
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Thats alot of power for drag radialsl to hook up. How old are the tires? How does it run on motor,does it hook up,spin or wheel hop? Do you know for sure that you are getting knock retard? Have you done any suspension work? Wheel hop is the tires loading up(gripping) and then slipping very quickly. It will break stuff. On my car I can't hook up on drag radials while spraying,even with a .5 sec delay. We need some more info on you combo.
11-12-2007, 03:23 PM
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no suspension work..stock IRS w 3.90s... drag radials are almost brand new.. DTE brace on trans/diff....motor runs were anemic at best. 13.xx ET with wheel hop and spin depending on launch.. no delay on spray..3000rpm - 6000rpm. not sure on KR.. just some opinions from trackside..would explain the shitting runs even after hooking 1-2 shift
11-12-2007, 04:24 PM
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suspenson, suspension, suspension.................the key to hooking up and not wheel hopping. i dropped the clutch at 5500 with my car and hooked with drag radials with 20-23 psi
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11-12-2007, 04:44 PM
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With the IRS on Corvettes my suspension options are very limited.
Last edited by Dr.Accumulator; 11-12-2007 at 04:50 PM.
11-12-2007, 05:21 PM
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11-12-2007, 06:40 PM
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i would take care of the wheel hop issue first. what is your current suspension set up? all you really need are a few bolt ons to solve 99% of wheel hop issues. #1 a good torque arm, #2 adjustable lower control arms, #3 LCA relo brackets. i doubt running an 18inch rim is helping your cause much either.
what software are you using for your data logging/tuning? if you don't have anything yet i woudl suggest HPTuners. you can log your runs and see exactly where the issues are occuring and make adjustments between passes.
what software are you using for your data logging/tuning? if you don't have anything yet i woudl suggest HPTuners. you can log your runs and see exactly where the issues are occuring and make adjustments between passes.
11-13-2007, 09:32 AM
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#1 a good torque arm, #2 adjustable lower control arms, #3 LCA relo brackets.
what software are you using for your data logging/tuning? if you don't have anything yet i woudl suggest HPTuners. you can log your runs and see exactly where the issues are occuring and make adjustments between passes.
what software are you using for your data logging/tuning? if you don't have anything yet i woudl suggest HPTuners. you can log your runs and see exactly where the issues are occuring and make adjustments between passes.
next track day ill have some logs to post..and some better ideas on KR
11-13-2007, 04:19 PM
#15
Had a similiar problem with my Cobra, my fix was to get rid of the drag radials and get some et streets. That eliminated all wheel hop! I believe the problem will be within the tires, an 18" drag radial has very little sidewall for flex so I would recommend a smaller diameter wheel and some stickier/bias ply tires!
11-13-2007, 08:25 PM
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Had a similiar problem with my Cobra, my fix was to get rid of the drag radials and get some et streets. That eliminated all wheel hop! I believe the problem will be within the tires, an 18" drag radial has very little sidewall for flex so I would recommend a smaller diameter wheel and some stickier/bias ply tires!
11-13-2007, 10:04 PM
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11-13-2007, 10:07 PM
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I would be more worried about the trap speed than anything. That car is not putting anywhere near 600 hp to the wheels @ 118 mph. My 3700 lb pig trapped 126 with an auto with less power. Sure the suspension & tires will drop your et, but it's not gonna do much of anything to your trap speed.
11-13-2007, 10:17 PM
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Had a similiar problem with my Cobra, my fix was to get rid of the drag radials and get some et streets. That eliminated all wheel hop! I believe the problem will be within the tires, an 18" drag radial has very little sidewall for flex so I would recommend a smaller diameter wheel and some stickier/bias ply tires!
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